Triplett BSX200 Basic Butt Set for Phone-Line Testing is a simple phone line tester capable of dial tone, dial out, caller ID, last number redial, on/off hang-up button, flash button, DTM and FSK support, last number redial, and 3 types of line plugs. The Triplett BSX200 features an RJ9 handset plug, insulated clips, a 66 block connect, and coupler. This model is great for those looking for a simple butt set capable of performing the standard tests, but avoiding the more expensive models with unnecessary, flashy features.